On December 12, 2007, Keyes participated in the Des Moines Register's Republican presidential debate, televised nationwide by PBS and the cable news networks. This was the first major presidential debate in which Keyes participated during the 2008 election season and the last Republican debate before the Iowa Caucuses. Although Keyes was not listed on the latest national CNN poll leading up to the debate, he registered with at least 1 percent of the Iowa vote in order to participate. During the debate, after the moderator began to ask a question of Texas Congressman Ron Paul, Keyes insisted he was not getting fair treatment. He interrupted the debate moderator at one point, saying that she had not called on him in several rounds and that he had to make an issue of it. He went on the offensive against his opponents during the debate, criticizing Rudy Giuliani's pro-choice position, as well as Mitt Romney's recent change in position on the same subject. In answering a question about global warming, he continued his criticisms of other candidates, saying, "I'm in favor of reducing global warming, because I think the most important emission we need to control is the hot air emission of politicians who pretend one thing and don't deliver". He also advocated ending the income tax, establishing state-sanctioned prayer in public schools, and abolishing abortion. Toward the end of the debate, Keyes stated he could not support Giuliani if he were to win the nomination due to the former New York mayor's position on abortion.